Practical examples of fire-extinguishing devices are known which are designed as spark-extinguishing systems for pipes which carry dust-laden gases. With these fire-extinguishing devices, pipes, which can have branches, run from a respective extinguishant reservoir each to at least one fire-extinguishing site. At the fire-extinguishing sites are located extinguishant nozzles which are fed from the extinguishant pipe and produce a fine spray in order to extinguish sparks.
In order to be able to achieve a desired extinguishing of sparks, the supply of extinguishant, particularly the supply of extinguishing water, is controlled by magnetic valves. The magnetic valves are connected to a control device in which signals supplied by spark detectors are evaluated and control signals for the magnetic valves are produced on the basis of the results of the evaluation.
The safety which is aimed for with such a fire-extinguishing device against dust explosions which can occur through unquenched sparks depends decisively not only upon the need for sparks which occur to be reliably detected, but also on the fact that after the detection of sparks an extinguishing of the sparks should follow immediately. It has been shown however that with the known fire-extinguishing devices noticeable time elapses between the first sensing of sparks and the complete formation of a spray.
It is an object of the invention to make available a fire-extinguishing device which has a short reaction time up to the triggering of the fire-extinguishing process.